The teacher or the meeting leader is a human. It means they could make few mistakes. Sometimes, they cannot realize that they made a mistake. This is because teachers are teaching same things over and over again. Especially teachers are teaching same thing constantly. It is totally possible to make a mistake. In my opinion, I would do interrupt and correct the mistakes right away.
First reason is that some students are not realized that the professor says something incorrect. If nobody says anything, most of students are learned incorrect explanation. Few students might realize that there is a mistake but they would not tell. Because they do not want to interrupt the professor. We can raise hand and wait until professor allow us to say something instead of interrupt the professor while he or she talks. Also, the professor would understand if we interrupt her for correcting. In my experience, if I correct teacher's mistake, she says thank you.In addition, after i correct her, I could hear most of students changing their notes.
Second reason is that it will affect us at last. What i mean is that is nobody correct the professor's mistake, then we are learning wrong opinion and it could affect our test. We thought it was correct but it was not. Let's say I knew that the meeting leader said wrong date of next meet and I say nothing. Eventually, it will cause huge problem. Every member misunderstand and leader did not know he or she made a mistake.
In conclusion, these two reasons why I would interrupt and correct mistake right away. As i said, the leader or teacher cannot notice if they made a mistake. It is important to correct them while everyone is together. If not, it can cause misunderstanding between the professor and students or meeting leader and members.